Photo by Mael Balland

An international collaboration between fishers and researchers is creating what scientists are calling a “transformational” dataset on ocean temperatures, one that promises to improve not only fishing operations but also the forecasting of significant weather events including marine heatwaves, cyclones, La Niña and El Niño.

Sensors recording water temperature and depth have been attached to fishing gear on boats working across waters in New Zealand, Australia, the Southern Ocean and the Western Central Pacific. More than 3 million recordings have been captured so far, creating a subsurface temperature dataset that is providing new insight into what is happening beneath the ocean surface, a rarity in some of the world’s most remote oceans.

Filling the knowledge gap beneath the surface

Professor Moninya Roughan, an oceanographer at the University of New South Wales who co-designed the sensors and leads the Fisheries Ships of Opportunity Observing Program (FishSOOP), explained the critical knowledge gap the programme addresses. Most global ocean temperature recordings are measured by satellites, but these can only record the temperature of the first centimetre of water.

“The oceans are on average 4 kilometres deep, so they are a vast reservoir,” she said. “We can get 10 to 15 to 20 degree temperature changes through the water column down to the bottom of the ocean.”

Whilst oceans are absorbing most of the excess heat from the atmosphere, understanding how that heat is distributed in space and at depth remains limited, particularly in data-sparse coastal and remote locations. Professor Roughan stressedthat continued observations are essential to better quantify where and how rapidly oceans are warming over time.

From cyclone prediction to seasonal forecasting

The implications for weather forecasting are substantial. “An extreme example of how the atmosphere is connected to the ocean are tropical cyclones, they feed off the heat content of the ocean,” Professor Roughan said. “If we can better estimate the heat content, we might have a better estimate of cyclone predictions, we might be able to save lives and property.”

Better ocean and atmospheric estimates could improve seasonal predictions, she continued: “If we can get a better estimate of the ocean and atmosphere today, we can make better estimates about the coming season, summer prediction next year or the year after.”

For the broader community, this would help forecast events like La Niña or El Niño and their impacts on rainfall, water supply and weather, whilst multi-decadal predictions would reveal the rate of ocean warming in specific regions and potential impacts.

“The FishSOOP program in my mind is transformational,” Professor Roughan said. “It’s transforming the way we work between scientists and industry, and how we measure and observe the ocean.”

Western Australian fishers join the programme

On Western Australia’s coast, the Western Rock Lobster Council has embraced the programme, with 10 boats along the coast from Mandurah to Kalbarri attaching sensors to their lobster pots. Matt Taylor, the council’s CEO, explained: “We’re quite keen to understand what’s happening at a pot level, rather than what’s happening on the surface.”

Currently, the sensors record temperature and depth, but Taylor said future iterations could include measurements of dissolved oxygen, pH and salinity. “We are trying to understand how the climate is effecting the waters in our fishery, but that would also benefit other fisheries on the west coast of WA,” he added.

A model for global ocean observing

Professor Roughan emphasised the necessity of partnership: “Ocean observing is difficult, but our planet is 70 per cent ocean. So we need to partner with industries to really be able to measure the ocean, we can’t do it with research funding alone. We are basically going along for the ride, fishing for ocean data while people go about their daily business doing their work and their fishing.”

The programme began in New Zealand before expanding to Australia in 2022. It now gathers data from fishers in the Southern Ocean and the Western Central Pacific, with partner organisations in the US, Japan and Europe working on similar programmes. Despite this expansion, gaps remain, and Professor Roughan is hoping more fishers will join FishSOOP to continue building this transformational dataset that bridges the gap between surface observations and the vast, heat-absorbing depths of the global ocean.